// this function is based on STM code
int machine_hard_i2c_readfrom(mp_obj_base_t *self_in, uint16_t addr, uint8_t *dest, size_t len, bool stop) {
machine_hard_i2c_obj_t *self = (machine_hard_i2c_obj_t*)self_in;
I2C_HandleTypeDef *hi2c = self->pyb->i2c;
uint32_t Timeout = *self->timeout;
/* Init tickstart for timeout management*/
uint32_t tickstart = HAL_GetTick();
#if 0
// TODO: for multi-master, here we could wait for the bus to be free
// we'd need a flag to tell if we were in the middle of a set of transactions
// (ie didn't send a stop bit in the last call)
/* Wait until BUSY flag is reset */
if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BUSY, SET, I2C_TIMEOUT_BUSY_FLAG, tickstart)) {
return -MP_EBUSY;
}
#endif
/* Check if the I2C is already enabled */
if ((hi2c->Instance->CR1 & I2C_CR1_PE) != I2C_CR1_PE) {
/* Enable I2C peripheral */
__HAL_I2C_ENABLE(hi2c);
}
/* Disable Pos */
hi2c->Instance->CR1 &= ~I2C_CR1_POS;
/* Enable Acknowledge */
hi2c->Instance->CR1 |= I2C_CR1_ACK;
/* Send Slave Address */
int ret = send_addr_byte(hi2c, I2C_7BIT_ADD_READ(addr << 1), Timeout, tickstart);
if (ret != 0) {
return ret;
}
if (len == 0U) {
/* Clear ADDR flag */
__HAL_I2C_CLEAR_ADDRFLAG(hi2c);
/* Generate Stop */
if (stop) {
hi2c->Instance->CR1 |= I2C_CR1_STOP;
}
} else if (len == 1U) {
/* Disable Acknowledge */
hi2c->Instance->CR1 &= ~I2C_CR1_ACK;
/* Clear ADDR flag */
__HAL_I2C_CLEAR_ADDRFLAG(hi2c);
/* Generate Stop */
if (stop) {
hi2c->Instance->CR1 |= I2C_CR1_STOP;
}
} else if (len == 2U) {
/* Disable Acknowledge */
hi2c->Instance->CR1 &= ~I2C_CR1_ACK;
/* Enable Pos */
hi2c->Instance->CR1 |= I2C_CR1_POS;
/* Clear ADDR flag */
__HAL_I2C_CLEAR_ADDRFLAG(hi2c);
} else {
/* Enable Acknowledge */
hi2c->Instance->CR1 |= I2C_CR1_ACK;
/* Clear ADDR flag */
__HAL_I2C_CLEAR_ADDRFLAG(hi2c);
}
while (len > 0U) {
if (len <= 3U) {
if (len == 1U) {
/* Wait until RXNE flag is set */
int ret = I2C_WaitOnRXNEFlagUntilTimeout(hi2c, Timeout, tickstart);
if (ret != 0) {
return ret;
}
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
} else if (len == 2U) {
/* Wait until BTF flag is set */
if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BTF, RESET, Timeout, tickstart)) {
return -MP_ETIMEDOUT;
}
/* Generate Stop */
if (stop) {
hi2c->Instance->CR1 |= I2C_CR1_STOP;
}
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
} else {
/* Wait until BTF flag is set */
if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BTF, RESET, Timeout, tickstart)) {
return -MP_ETIMEDOUT;
}
/* Disable Acknowledge */
hi2c->Instance->CR1 &= ~I2C_CR1_ACK;
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
/* Wait until BTF flag is set */
if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BTF, RESET, Timeout, tickstart)) {
return -MP_ETIMEDOUT;
}
/* Generate Stop */
if (stop) {
hi2c->Instance->CR1 |= I2C_CR1_STOP;
}
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
}
} else {
/* Wait until RXNE flag is set */
int ret = I2C_WaitOnRXNEFlagUntilTimeout(hi2c, Timeout, tickstart);
if (ret != 0) {
return ret;
}
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
if (__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_BTF) == SET) {
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
}
}
}
return 0;
}
/**
* @brief Receives in master mode an amount of data in blocking mode.
* @param hi2c Pointer to a I2C_HandleTypeDef structure that contains
* the configuration information for the specified I2C.
* @param DevAddress Target device address The device 7 bits address value
* in datasheet must be shifted to the left before calling the interface
* @param pData Pointer to data buffer
* @param Size Amount of data to be sent
* @param Timeout Timeout duration
* @param LastOp If set sends STOP, otherwise no STOP
* @retval HAL status
*/
HAL_StatusTypeDef HAL_I2C_Master_Receive_Custom(I2C_HandleTypeDef *hi2c,
uint16_t DevAddress, uint8_t *pData, uint16_t Size, uint32_t Timeout,
uint8_t LastOp)
{
uint32_t tickstart = 0U;
uint8_t prev_mode = 0;
HAL_StatusTypeDef rc;
if (hi2c->State == HAL_I2C_STATE_READY)
{
/* Process Locked */
__HAL_LOCK(hi2c);
/* Init tickstart for timeout management */
tickstart = HAL_GetTick();
prev_mode = hi2c->Mode;
if (prev_mode != HAL_I2C_MODE_MASTER_SEL)
{
if (I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BUSY, SET, I2C_TIMEOUT_BUSY, tickstart) != HAL_OK)
{
return HAL_TIMEOUT;
}
}
hi2c->State = HAL_I2C_STATE_BUSY_RX;
hi2c->Mode = HAL_I2C_MODE_MASTER;
hi2c->ErrorCode = HAL_I2C_ERROR_NONE;
/* Prepare transfer parameters */
hi2c->pBuffPtr = pData;
hi2c->XferCount = Size;
hi2c->XferISR = NULL;
/* Send Slave Address */
/* Set NBYTES to write and reload if hi2c->XferCount > MAX_NBYTE_SIZE and generate RESTART */
if (hi2c->XferCount > MAX_NBYTE_SIZE)
{
hi2c->XferSize = MAX_NBYTE_SIZE;
I2C_TransferConfig(hi2c, DevAddress, hi2c->XferSize, I2C_RELOAD_MODE, I2C_GENERATE_START_READ);
}
else if (!LastOp)
{
hi2c->XferSize = hi2c->XferCount;
I2C_TransferConfig(hi2c, DevAddress, hi2c->XferSize, I2C_SOFTEND_MODE, I2C_GENERATE_START_READ);
}
else
{
hi2c->XferSize = hi2c->XferCount;
I2C_TransferConfig(hi2c, DevAddress, hi2c->XferSize, I2C_AUTOEND_MODE, I2C_GENERATE_START_READ);
}
while (hi2c->XferCount > 0U)
{
/* Wait until RXNE flag is set */
rc = I2C_WaitOnRXNEFlagUntilTimeout(hi2c, Timeout, tickstart, prev_mode);
if (rc != HAL_OK && rc != HAL_NACK)
{
if (hi2c->ErrorCode == HAL_I2C_ERROR_AF)
{
return HAL_ERROR;
}
else
{
return HAL_TIMEOUT;
}
}
/* Read data from RXDR */
(*hi2c->pBuffPtr++) = hi2c->Instance->RXDR;
hi2c->XferSize--;
hi2c->XferCount--;
if (rc == HAL_NACK)
{
break;
}
if ((hi2c->XferSize == 0U) && (hi2c->XferCount != 0U))
{
/* Wait until TCR flag is set */
if (I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_TCR, RESET, Timeout, tickstart) != HAL_OK)
{
return HAL_TIMEOUT;
}
if (hi2c->XferCount > MAX_NBYTE_SIZE)
{
hi2c->XferSize = MAX_NBYTE_SIZE;
I2C_TransferConfig(hi2c, DevAddress, hi2c->XferSize, I2C_RELOAD_MODE, I2C_NO_STARTSTOP);
}
else if (!LastOp)
{
hi2c->XferSize = hi2c->XferCount;
I2C_TransferConfig(hi2c, DevAddress, hi2c->XferSize, I2C_SOFTEND_MODE, I2C_NO_STARTSTOP);
}
else
{
hi2c->XferSize = hi2c->XferCount;
I2C_TransferConfig(hi2c, DevAddress, hi2c->XferSize, I2C_AUTOEND_MODE, I2C_NO_STARTSTOP);
}
}
}
if (LastOp)
{
/* No need to Check TC flag, with AUTOEND mode the stop is automatically generated */
/* Wait until STOPF flag is set */
if (I2C_WaitOnSTOPFlagUntilTimeout(hi2c, Timeout, tickstart) != HAL_OK)
{
if (hi2c->ErrorCode == HAL_I2C_ERROR_AF)
{
return HAL_ERROR;
}
else
{
return HAL_TIMEOUT;
}
}
/* Clear STOP Flag */
__HAL_I2C_CLEAR_FLAG(hi2c, I2C_FLAG_STOPF);
}
else
{
/* No autoend/reload was requested, make sure transmission of last byte
* has finished... */
if (I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_TC, SET, Timeout, tickstart) != HAL_OK)
{
return HAL_TIMEOUT;
}
}
/* Clear Configuration Register 2 */
I2C_RESET_CR2(hi2c);
hi2c->State = HAL_I2C_STATE_READY;
if (LastOp)
{
hi2c->Mode = HAL_I2C_MODE_NONE;
}
else
{
hi2c->Mode = HAL_I2C_MODE_MASTER_SEL;
}
/* Process Unlocked */
__HAL_UNLOCK(hi2c);
return HAL_OK;
}
else
{
return HAL_BUSY;
}
}
